Editor's Note: Bill Rhodes is a Senior Advisor for Citi, after more than 53 years with the institution. He most recently served as Senior Vice Chairman of Citigroup and Citibank. His work in international financial diplomacy in the 1980s and 1990s helped manage the debt crisis that involved developing nations and their creditors worldwide. He is chair of an Asia Society report on the problem.

(CNN) -- The Group of 20 Summit in Seoul, South Korea, on November 11 and 12, may be the most important meeting of this group to date.

Finance ministers and central bank governors preparing the summit said all the right things at the recent Washington annual meetings of the IMF and World Bank -- noting how fragile economic conditions are, warning of the risks of protectionism, voicing concern about currency movements and the need to address underlying payments balances, and calling for agreement on tough financial regulatory reform.

But, now it is time to stop the pontificating and act. The G-20 summit will be judged on the decisions it takes and how these are implemented.

The summit leaders should understand that their actions will impact market confidence. Stimulating private investment, which is the key to securing growth and employment in the Euro-Area, the United States and Japan, requires policy decisions that rebuild the market confidence that was shattered by the 2008/2009 financial crisis.

The London G-20 summit in April 2009, responded well and signaled prospects well coordinated policy actions. That momentum has now petered out.

Each of the issues on the G-20 agenda relates to the paramount challenge of placing the world economy on a more stable path. The G-20 should publicly recognize that economic conditions in each of its member countries differ and that each needs to be able to take appropriate short-term measures to secure growth, so long as these do not damage prospects for others.

Overhanging global prospects, however, are formidable budget deficits and national debts -- the skyrocketing gold and other commodity prices suggest that investors see public finances as being out of control.

President Obama should lead a G-20 agreement, to be announced on November 12, involving credible blueprints by the governments of each of the major mature economies for medium-term fiscal consolidation, which is essential for growth and for reducing unemployment substantially. Without clear numbers and timetables any governmental statements in Seoul on this front will have a hollow ring.

Skyrocketing gold and other commodity prices suggest that investors see public finances as being out of control--Bill Rhodes

All of the G-20 partners will need to understand that such commitments will require sacrifices by the citizens of the developed economies. In the medium-term, for example, social entitlement programs may have to be cut. In return, the leaders of these economies should seek a summit agreement by all G-20 participants for an immediate halt to currency market intervention.

This should be accompanied by an agreement to hold a special meeting before the end of this year, convened by the IMF, that addresses core issues of international payments imbalances. If this does not happen, then markets could react and "currency wars" could develop.

In addition, addressing the issues of exchange rates and currency imbalances is the best path to deterring protectionist measures. And, it is high time for the summit to set a firm and final date for signing a Doha Round trade pact. The longer the prevarication, the greater is the risk of unleashing beggar-thy-neighbor trade actions.

In a world of greater clarity about medium-term fiscal consolidation, exchange rate understandings and open trade, it will be easier for central banks to pursue short- and medium-term national monetary policies that do not have unintentional negative foreign consequences.

Right now, in a world of abundant liquidity, all the negative market perceptions about the policies of the developed economies, plus very low interest rates, are driving investors to chase yield and move capital into the best performing emerging markets. If sustained, this will threaten the economic performance of these well managed and sound economies.

Building confidence about the policy outlook in the developed economies, which G-20 agreements can help, will relieve otherwise damaging pressures on emerging markets. Given the risks here, the central banks of the developed economies need to be both cautious about the ways in which they contribute to domestic economic growth in the short-term and clear that they have medium-term intentions to contain monetary growth.

The final critical component of the G-20 agenda is financial regulatory reform. All the officials, and most bankers, agree that reforms are needed to make the financial system more resilient and this requires more than just lip service to ensuring consistent coordination across national borders of agreements determined by the Basel Committee, the Financial Stability Board, as well as the setters of accounting standards.

Unless there is meaningful coordination there will be a high risk of regulatory arbitrage. And, right now there is reason to be concerned as statements by an assortment of national authorities suggest they view the recent Basel III agreements as a minimum, that they plan to add requirements and possibly shorten the implementation timetable. This will add to the economic costs of regulatory reform and with many millions of people unemployed, the world economy cannot afford that.

The G-20 summit should declare an agreement on the new Basel III proposals and a standstill by all national bank regulatory authorities on any actions that will add further to the costs of bank capital. In this area, as in all others on the agenda, a powerful demonstration of multilateral agreement and common sense is now required.